Modern Malware: Viruses, Worms and Trojan Horses
Today's Internet is a hall of wonders. In the wrong hands, though, it can quickly become a house of horrors. Invasive software known as malware can quietly infect your PC at any time, threatening to destroy your computer's speed, your financial security and even your identity.
The good news is that malware is usually avoidable. PC makers and software geeks have spent years refining their systems to prevent unwanted attacks, and today most malware cannot simply install itself.
The bad news? Hackers and criminals have become adept at exploiting something far more reliable: user error. Click the wrong link or open a bad email, and you could find your PC surrendering to an invading army in a matter of seconds.
The only sure way to avoid such threats is to know thy enemy. With that in mind, here's a list of the top malware threats:
The virus remains the godfather of all malware. These little snippets of code attach themselves to the programs running on your PC. When you open the program, the virus runs. What it does from there is often anyone's guess: it could do something as innocuous as making copies of itself, or as nasty as searching your computer for credit-card information.
Tip: Viruses and their host programs must be opened to run. If you've downloaded any software from a site you've never heard of, run a scan first using your antivirus software. You should stick with software vendors you know and trust.
One especially aggressive kind of virus is the worm. Unlike a traditional virus, which requires a program to be opened, worms can do their dirty work without any assistance at all. You could be off the PC and out of town, and that worm will continue to tunnel into your computer's files, make copies of itself, and worse. Like viruses, worms can perform all kinds of evil tasks, from sending infected emails to your friends to installing special software (known as a keylogger) that records everything you type.
Tip: Worms tend to infect computers through risky activities such as opening dangerous Web sites or clicking links in spam emails. Avoiding these threats should keep your PC free of creepy crawlies.
Trojans, or Trojan Horses, are without doubt the most deceptive member of the group. What makes Trojans especially insidious is how they get into your PC in the first place. Trojans arrive disguised as legitimate software. That software may have the same name and icon as a familiar program, which can make it difficult to distinguish real from fake. But open it up, and you'll feel like you've opened Pandora's box. Suddenly a new bad guy has been set loose on your files and privacy.
Tip: Trojans must be downloaded and installed by the user, so never install software from anyone other than a legitimate vendor. When in doubt, check the address at the top of your browser to make sure you're on the site of, say, Staples (not Stapels).
The best way to fight malware of every stripe is simply to avoid the tricks that malware programmers love: spammy Web sites, fake emails, bogus financial documents and suspicious links on the Web. Stay within the good neighborhoods of the Web, double-check all emails and financial notices, and click only when confident.
The bottom line when it comes to the modern malware threat? Education remains the best security system around.